ABSTRACT
OBJECTIVE: To explore the effect of~(56)Fe~(17+)heavy ion on the expression of phosphorylated histone H2AX( γH2AX) of human lymphccytes. METHODS: The Epstein-Barr virus transformed human B lymphocyte cell lines( PengEBV) were selected and exposed to~(56)Fe~(17+)heavy ion at irradiation dose of 0. 0( control group),0. 1,0. 3,0. 5,0. 7,1. 0 and 2. 0 Gy,respectively,with the dosing rate of 0. 23-0. 55 Gy / min. Flow-cytometry was used to detect the changes of expression of γH2AX at time points of 0,2,4,8,48 and 72 hours after irradiation. RESULTS: The expression of γH2AX showed interaction existed between radiation dose and the treatment time after radiation( P < 0. 01). Compared with the control at the same time points,the expression of γH2AX increased at the dose of 0. 3-2. 0 Gy and the time points of 2-72hours( P < 0. 05). The expression of γH2AX at the dose of 0. 3-2. 0 Gy and time points of 8-72 hours was lower than those at the same dose and time points of 2 and 4 hours( P < 0. 05). When the dose was at 0. 5,1. 0 or 2. 0 Gy,the expression of γH2AX decreased with the increasing time of exposure in 72 hours( P < 0. 05). At the dose of 0. 0-1. 0 Gy and the time points of 2-4 hours,the expression of γH2AX increased with the increasing dose of irradiation( P < 0. 01). CONCLUSION: The expression of γH2AX in Peng-EBV cells shows a dose-response relationship within 2-4 hours after 0. 0-1. 0 Gy irradiation of~(56)Fe~(17+).
ABSTRACT
To investigate the inhibitory effects of RNAi expression vector on CaMKⅡ? expression of PC12 cell lines. siRNA expression vectors were constructed to be targeted directly at CaMKⅡ? gene. The recombinants were transfected into PC12 cell line with liposome. The expression of CaMKⅡ? was detected by RT-PCR and Western blot. Expression vectors could reduce the expressions of CaMKⅡ? mRNA and protein in PC12, Compared with blank vector group, the former, the ratio of inhibition of the expression of CaMKⅡ? mRNA was 46.40% and 64.69%, in 48th hour and 72th hour, the ratio of inhibitory of the expression of CaMKⅡ? protein was 74.77% in 72th hour. RNAi expression vectors can effectively inhibit the expression of CaMKⅡ? in PC12.